Norilsk Nickel, the Russian nickel producer at the centre of a takeover battle, is the first target of a new activist investor group which aims to put pressure on polluting companies and industries.
Environmental Investor Services, which is funded by monthly fees from investors, said it will work as a middleman for investors who are concerned about green issues but "do not wish to put their head above the parapet".
"There are a lot of investors out there who want to be green and a lot of companies who like to say they are green but are not as environmentally friendly as they claim to be," said Damien McCrystal, founder of Environmental Investor Services.
Norilsk Nickel, the world's largest nickel producer, faces merger proposals from two Russian oligarchs: Oleg Deripaska, who controls the aluminium producer Rusal, and the metals tycoon Alisher Usmanov.
Norilsk's chief executive, Denis Morozov, was recently in London to canvass investor support as it tries to fight off a bid from Rusal, and Mr McCrystal said this was an opportunity for shareholders "to look in greater detail at Norilsk and its social and environmental track record".
The city of Norilsk, where the company is based, was named as one of the world's 10 most polluted places last year by the Blacksmith Institute, a New York-based anti-pollution group.
"A shift in power brought about by one of these proposed mergers could end decades of inertia," Mr McCrystal said. "It is very important at this stage for any shareholder who cares anything for the environment to make their views clear to the rival bidders. That way, we might secure some binding agreements about how the company's pollution will be controlled in the future."
Last week, Russia's environmental watchdog, the Natural Resources Ministry, named Norilsk Nickel in a $178m (£89.7m) pollution lawsuit, over alleged pollution of rivers in India. Norilsk denies the agency's findings.